Antiretroviral drugs were associated with “silent” heart disease in a group of HIV-positive cocaine users, according to the authors of a study published in the February 15 issue of Clinical Infectious Diseases.

Doctors identify heart disease as being “silent” when a person is found to have narrowing of the arteries that supply oxygen-rich blood to the heart, called coronary stenosis, but whose other typical measures of heart disease, such as blood pressure and cholesterol levels, are normal.

Shenghan Lai, MD, PhD, of the Johns Hopkins School of Medicine, and his colleagues enrolled 165 African-American HIV-positive adults with a history of cocaine use, but who had normal blood pressure, body mass index and cholesterol levels. The participant group’s average age was 45, and nearly all were smokers. Dr. Lai’s group conducted computed tomography (CT) scans of the participants’ coronary arteries to detect stenosis.

Overall, 15 percent of the study participants were found to have coronary stenosis. People who’d been using cocaine for 15 or more years were almost three times as likely to have coronary stenosis as those who had been using cocaine for less than 15 years. When Lai’s team controlled for cocaine use and other risk factors, they found that the use of antiretrovirals was also associated with coronary stenosis, and the result was statistically significant, meaning that the difference was too great to have happened by chance.

When Lai’s team sought to determine if specific antiretrovirals were more associated with coronary stenosis than others, they found that the use of Combivir (zidovudine plus lamivudine) and Zerit (stavudine) was more commonly associated with coronary stenosis.

The authors caution against interpreting the results as applicable to all populations of people living with HIV. First, they acknowledge that, because participants took combinations of antiretrovirals, it is difficult to tease out the individual contribution of any of the drugs to coronary stenosis. Also, the population was made up of people at much higher risk for stenosis—African-American smokers with a significant history of cocaine use—and was not compared with HIV-positive people on antiretroviral therapy without these risk factors. They do, however, feel that the proportion of participants found to have “silent” heart disease, 15 percent, is significant.